INFO: task syz.0.3472:21863 blocked for more than 163 seconds. Not tainted 6.14.0-rc5-syzkaller-00105-gf315296c92fd #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.3472 state:D stack:27920 pid:21863 tgid:21862 ppid:17560 task_flags:0x400140 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6857 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6914 __mutex_lock_common kernel/locking/mutex.c:662 [inline] __mutex_lock+0x6bd/0xb10 kernel/locking/mutex.c:730 nfsd_nl_threads_set_doit+0x694/0xbe0 fs/nfsd/nfsctl.c:1629 genl_family_rcv_msg_doit+0x202/0x2f0 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x565/0x800 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2533 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline] netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1338 netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1882 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:733 [inline] ____sys_sendmsg+0xaaf/0xc90 net/socket.c:2573 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2627 __sys_sendmsg+0x16e/0x220 net/socket.c:2659 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff00658d169 RSP: 002b:00007ff0074cd038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007ff0067a5fa0 RCX: 00007ff00658d169 RDX: 0000000000000810 RSI: 0000400000002640 RDI: 0000000000000003 RBP: 00007ff00660e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ff0067a5fa0 R15: 00007ffd5f1c1c68 INFO: task syz.4.3516:22055 blocked for more than 142 seconds. Not tainted 6.14.0-rc5-syzkaller-00105-gf315296c92fd #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.3516 state:D stack:26752 pid:22055 tgid:22052 ppid:12899 task_flags:0x400140 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6857 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6914 __mutex_lock_common kernel/locking/mutex.c:662 [inline] __mutex_lock+0x6bd/0xb10 kernel/locking/mutex.c:730 nfsd_nl_listener_set_doit+0xe3/0x1b40 fs/nfsd/nfsctl.c:1922 genl_family_rcv_msg_doit+0x202/0x2f0 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x565/0x800 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2533 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline] netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1338 netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1882 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:733 [inline] ____sys_sendmsg+0xaaf/0xc90 net/socket.c:2573 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2627 __sys_sendmsg+0x16e/0x220 net/socket.c:2659 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f239538d169 RSP: 002b:00007f23931d5038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f23955a6080 RCX: 00007f239538d169 RDX: 0000000000004000 RSI: 0000400000000000 RDI: 0000000000000006 RBP: 00007f239540e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f23955a6080 R15: 00007ffdfaaf7698 Showing all locks held in the system: 2 locks held by kworker/1:0/25: 1 lock held by khungtaskd/30: #0: ffffffff8e1bd0c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e1bd0c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e1bd0c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6746 2 locks held by getty/5591: #0: ffff888035cda0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211 4 locks held by kworker/u8:10/18592: #0: ffff88801bef5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213 #1: ffffc9000d807d18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214 #2: ffffffff8fee3d10 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xca/0xb30 net/core/net_namespace.c:606 #3: ffffffff8fef9a28 (rtnl_mutex){+.+.}-{4:4}, at: mpls_net_exit+0x83/0x350 net/mpls/af_mpls.c:2706 2 locks held by syz.3.3425/21637: 2 locks held by kworker/u8:31/21661: 2 locks held by syz.0.3472/21863: #0: ffffffff8ff9a7b0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e5c03a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x694/0xbe0 fs/nfsd/nfsctl.c:1629 2 locks held by syz.4.3516/22055: #0: ffffffff8ff9a7b0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e5c03a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xe3/0x1b40 fs/nfsd/nfsctl.c:1922 2 locks held by syz-executor/22079: #0: ffff88804667c0e0 (&type->s_umount_key#49){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff88804667c0e0 (&type->s_umount_key#49){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88804667c0e0 (&type->s_umount_key#49){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:505 #1: ffffffff8e5c03a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 2 locks held by syz-executor/23000: #0: ffff88807a6300e0 (&type->s_umount_key#49){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff88807a6300e0 (&type->s_umount_key#49){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88807a6300e0 (&type->s_umount_key#49){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:505 #1: ffffffff8e5c03a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 2 locks held by syz-executor/23166: #0: ffff88807192c0e0 (&type->s_umount_key#49){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff88807192c0e0 (&type->s_umount_key#49){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88807192c0e0 (&type->s_umount_key#49){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:505 #1: ffffffff8e5c03a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 2 locks held by syz.6.3675/23313: 2 locks held by syz.9.3693/23524: #0: ffffffff8ee8a468 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2046 [inline] #0: ffffffff8ee8a468 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf80 drivers/tty/tty_io.c:2129 #1: ffff88807f7991c0 (&tty->legacy_mutex){+.+.}-{4:4}, at: tty_init_dev.part.0+0x37/0x660 drivers/tty/tty_io.c:1415 1 lock held by syz.9.3693/23526: #0: ffffffff8ee8a468 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2046 [inline] #0: ffffffff8ee8a468 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf80 drivers/tty/tty_io.c:2129 1 lock held by syz.1.3696/23650: #0: ffffffff8ee8a468 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2046 [inline] #0: ffffffff8ee8a468 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf80 drivers/tty/tty_io.c:2129 1 lock held by syz.5.3702/23754: #0: ffffffff8ee8a468 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2046 [inline] #0: ffffffff8ee8a468 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf80 drivers/tty/tty_io.c:2129 1 lock held by syz.3.3707/23834: 1 lock held by syz.4.3706/23971: #0: ffffffff8ee8a468 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2046 [inline] #0: ffffffff8ee8a468 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf80 drivers/tty/tty_io.c:2129 3 locks held by syz-executor/24019: 1 lock held by syz.0.3717/24055: #0: ffffffff8e1c8400 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x700 kernel/rcu/tree.c:3741 2 locks held by syz.0.3717/24057: 1 lock held by sed/24065: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.14.0-rc5-syzkaller-00105-gf315296c92fd #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline] watchdog+0xf62/0x12b0 kernel/hung_task.c:399 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244